Improvement in the construction of reverberatory and melting furnaces



UNITED STATES PATENT OEEIcE.

ABIAL ELLIOT OF SOUTH VVOLFBOROUGH, NEW HAMPSHIRE.

IMPROVEMENT IN THE CONSTRUCTION OF REVERBERATORY AND MELTING FURNACES.

Specification forming part of Letters Patent No. 90,515, dated May 25,1869 To all whom 'it may concern:

Be it known that I, ABIAL ELLIOT, of South Wolf borough, Carroll county,State of New Hampshire, have invented new and useful Improvements in theConstruction of a Melting-Furnace, and which I call a Hot- Air, DoubleReverberatory Anthracite Melting-Furnace and that the following is afull and exact description of my said improvements, reference being hadto the drawings accompanying and making part of this my Specification.

Figure I of the drawings represents a vertical longitudinal section ofthe furnace on line a; ac in Fig. III. Fig. II represents afrontelevation, partly in section. Fig. III represents a cross-section of thefurnace at the line zz in Fig. I. Fig. IV is a horizontal longitudinalsection of the furnace on the line w ur in Fig. I.

In all the figures the same letters represent the same parts. V

My invention has reference, primarily, to increasing the ignition of theanthracite fuel used in such furnace, and to intensifying the heat andpreserving its very greatly-increased temperature at a uniform degree bythe arrangements of the flues and hot-air pipes, so as that the wasteheat of the furnace heats to a very high degree the hot-air pipes andthe hot blast passing through them; secondly, to the arrangement of thegrates in connection both with the melting-chamber and to the receptionof the hot blast; thirdly, to the construction of a double or auxiliarygrate in connection with the principal grate, where the combustion iscompleted, for the purpose of properly heating and coking the fuel forits combustion; and, fourthly, to the construction and arrangement of acoal hopper or reservoir adapted to said grates, for the purpose ofavoiding the opening of doors, and preventing the admission of cold airinto the furnace during the heat or melting of the metal.

The construction of the furnace and the nature and operation of myimprovements will now be described.

Fig. I of the drawing exhibits the interior parts of the furnance, inwhich A is the tire-chamber; B, the bridge-wall; C, the hearth, wherethe metal receives the heat and is melted.

I) is a side ue, descending and communicatin g with the heating-chamberE under the hearth, and where the pipes for heating the blast andconducting it to the fuel are arranged. This heating-chamber E extendsunder the furnace its whole length, and the heat passes off out of itinto the chimney-Hue at E.

The heating-pipes of the blast are shown at F1 F1. These are connectedtogether by the horizontal cross-pipe F2. This pipe F2 extends acrossthe rear of the furnace. 'It opens at either end into chambers orair-flues H H', Figs. II, III, and IV, on each side of the fur'- nace,and into which side flues the air from the blast is introduced throughthe pipes I Il I2, Fig. III. The several hot-air pipes F Fl dischargethe heated air into the chamber F3, leading directly under the principalfire-grate.

A is the ash-pit, closed by air-tight doors K when the-furnace is inoperation. A

l The grate for fuel is a compound grate, composed of two parts-thelower, which is the principal or main grate,.and the upper or auxiliarygrate.`

The main grate a is placed at an angle of about forty-tive degrees, itslower end reaching to the pit of bridge-wall B, its upper end resting ona bridge-wall, b, which bridge-wall b is interposed between the twogrates.

The auxiliary or feeding grate cis also placed about the same angle, andextends from the bridge-wall b to the opening in the bottom of hopper orreservoir d, in which the fuel is placed, and which holds sufficient tomelt the charge.

The bars of grate c are all secured on a square transverse bar, c, onwhich the grate is made to swing, and is operated by the lever cf", Fig.III.

The object of the auxiliary grate c is twofold, as when the hopper d islled with fuel it descends and fills the grate c to the top ofbridge-wall b. It is there held, and it may be prepared, heated, orcoked for burning upon the main grate by permitting the hot blast toascend through the slot gl in the plate g, the degree of which isregulated by slide g2; and, further, the fuel on grate c, thus preparedor coked, is moved down upon the main plate a, when needed, by operatingupward the swinging grate c by means of the lever c2, which is therebypart-1y pushed over bridge-block b, and

distributed over the main grate a,'thus obviating the necessity ofopening a feed or tire i any parts, and if clinkersl or otherobstructions have formed they may be removed.

u it are steam-pipes, through which steam is blown over the hearth ofthe furnace. Steam is also introduced at n with the cold air from theblast.

A suitable pipe, f, Fig. I, is provided, by which hot air may beconducted from the hotair pipes upon the top of the fuel on grate c whenrequired.

An opening for stirring the metal when required is made in the side wallat O. The tapping-hole for the melted metal is at p. A tapping-hole fordrawing off the flux, when required, is provided at q.

In the upper part of the front of the furnace is a door, S', openinginto the heatingchamber, by which the metal is introduced into thefurnace.

By this construction and arrangement of the furnace the hot-air pipesand the air from the blast passing through them are enveloped v in theheat from the main heating-chamber.

The air is prepared for entering the heatingpipes by being warmed beforeentering them, by passing along the side walls of the furnace, and theheat of the blast is gradually increased as the blast in the air-pipesproceeds against or in an opposite direction to the current of heat fromthe furnace. The air of the blast thus becomes heated to an extremelyhigh temperature, thus adding to the intensity of the ignition, andconsequent heat of the furnace.

A sufficiency of fuel is provided for melting the charge, and the fuelis prepared or coked and pushed down and distributed by and from theauxiliary grate c upon the main grate a.

The furnace thus constructed produces a more intense heat and more rapidfusion of the metal than any melting-furnace hitherto constructed, andwith less danger of the metal being injured by the introduction of theeX- ternal air during the process, which is of great importance wheniron is melted for refining, or if being converted into steel.

The heat to which the hot-blast pipes F1 are subjected is so intense asto require that they be strengthened and braced to prevent warping andcracking. AThey may be made of iron;V

interior be composed of the best-known materials for resisting theeffects ofthe heat.

The introduction of jets vof steam adds to the intensity of combustion;but I do not claim this as any part of my invention. l

I do not claim as my invention the conducting the waste heat of thefurnace by a downward iiue under the hearth, as this is not new.

Nor do I claim any of the parts of the interior heating-chamber or ofthe shell or walls of the furnaceythese parts used by me being common todouble reverberatory furnaces, such as are used in large foundries.

I do not wish it understood that my invention applies only to the use ofvanthracite coal in such furnaces. I have describedrthe furnace asY ananthracite-furnace, because I believe tha fuel to be decidedly the best;but other kinds of coal may be used.

' I claim as my invent-ion, and desire Letters Patent for the featuresand improvements following, to wit:

l. The manner of arranging the hotair pipes for heating the blastlongitudinally in a chamber under the hearth, so as to receive and inthis manner utilize the whole Waste heat of the furnace through theirentire length,

and which chamber forms a part or continuation of the main flue, andentirely incloses the heating-pipes.

2. I claim the construction and arrangement of the two parts a and c,combined with the coal hopper or reservoir, operating for the purposeand in the manner substantially as described.

3. I claim the construction of the auxiliary grate, arranged andcombined with the bridgewall b and the main grate a, so as t-o preparethe fuel, and also push it forward when required, and distribute it uponthe main grate, substantially as described.

4. I claim the slotted plate and slide g glgz, by which the separatechamber under grate c is provided, and by and through which theadmission of the hot air from the blast under grate c may be regulated,in the manner and for the purpose substantially as described.

ABIAL ELLIOT. [1.. s.)

Witnesses:

CHAs. S. BEAOHAM, J oHN H. RUST.

